Why do certain ways of getting a button's title not work?

Question

I'm trying to get the title of a UIButton. The docs mentioned a few different ways of doing this, so I tried out a few of them with mixed results.

I dropped a button on the canvas (I'm using Storyboard, not SwiftUI), connected it to an IBAction, and tested out getting the title with the following code:

@IBAction func printTitle(_ sender: UIButton) {
    if let buttonTitle = sender.titleLabel?.text {
        print("title label text:", buttonTitle)
    } else {
        print("Title label text doesn't exist")
    }
    
    if let buttonTitle = sender.configuration?.title {
        print("configuration title:", buttonTitle)
    } else {
        print("configuration title doesn't exist")
    }
    
    if let buttonTitle = sender.currentTitle {
        print("current title:", buttonTitle)
    } else {
        print("Current title doesn't exist")
    }
    
    if let buttonTitle = sender.title(for: .normal) {
        print("title for normal state:", buttonTitle)
    } else {
        print("Title for normal state doesn't exist")
    }
    
    if let buttonTitle = sender.title(for: .selected) {
        print("title for selected state:", buttonTitle)
    } else {
        print("Title for selected state doesn't exist")
    }
    
    if let buttonTitle = sender.title(for: .highlighted) {
        print("title for highlighted state:", buttonTitle)
    } else {
        print("Title for highlighted state doesn't exist")
    }
}

After clicking the button, I end up getting the following output (the button's title is 'Hello'):

title label text: Hello
configuration title: Hello
Current title doesn't exist
Title for normal state doesn't exist
Title for selected state doesn't exist
Title for highlighted state doesn't exist

I tested this out with a few different built-in button types (System and Detail Disclosure) and the same thing happens. Why does the title(for:) method and the currentTitle property not work? What is the best way to get a button's title?

Here is a link to an Xcode project with just the button and the IBAction above in ViewController.swift: https://github.com/msotoTTP/test1.